The mRNAs from the newt lens will be extracted, and characterized by translation in a cell free system. The products of translation will be compared with the crystal lins of the normal lens and newly regenerated lens by immunoprecipitation, SDS-polyacrylamide gel electrophoresis, isoelectric focussing in a polyacrylamide gel, and tryptic peptide analysis. The mRNAs will be hybridized with cloned alpha-, beta-, and delta-crystallin cDNAs which will permit direct detection and partial quantitation of crystallin mRNAs. mRNAs from lenses that form from iris cultured in the presence of insulin, NGF or FGF will also be isolated and subjected to the same analyses as the lens in vitro. Transmission and scanning electron microscopic studies of iris, stimulated to transform into lens cells by growth factors is also planned. Changed in iris cell organelles will be noted as well as the structural bases for the process. Future plans include studies of the appearance, accumulation and quantitation of mRNAs - specific for crystallins during lens regeneration. RNA accumulation and utilization is believed to have a significant role in controlling cellular differentiation. Studies that relate to mechanisms that control gene expression are basic tothe biological sciences due to the myriad of such checks and balances that operate, for example, during embryonic development, normal physiological regeneration and wound healing and many physiological mechanisms. Uncontrolled cell activities such as proliferation that we see in cancer, could be better understood if we had more information concerning these events at the molecular level.